Process of treating coal with oil



1 undesirable compounds. This is true of low- Patented Apr. 25, 1933 .O'O'QU'NIOTED ST TE PATENT .Q F i EAR LD .1. ROSE, or PENN TOWNSHIP, ALLEGHENY COUNTY, PENNSYLVANIA, AND

WILLIAM H. HILL, OF NEW YORK, N. Y., ASSIGNORS TO THE KOPPERS COMPANY OF DELAWARE, -'.A CORPORATION OF DELAWARE rnoonss or TREATING ooAL wrr r OIL No Drawing. Application filed April 12,

This invention relates to a process for treating tars and oils, and more particularly to a process for increasing the solvent properties of tars and oils wlth respect to coal. It has been pointed out in our co ending application, Serial No. 97 ,467 filed arch 25, 1926, that coal is soluble in only a restricted group of materials. It is stated substantially that water-gas tar for instance may be improved for this purpose by distilling off temperature tar also, but the procedure is not always applicable from an economic standpoint. v

It has been found that oilssuch as coke oven tar oils and cracked petroleum oils may be rendered more efiective and in general, tars and oils may be improved for the dissolving of coal by treating them with a dchydrogenating agent such as sulphur or. oxygen, or a combination of these. The process is preferably carried on at elevated temperatures, with or without the use of catalysts. At lower temperatures, the period of treatment is relatively longer than at higher temperatures.

In this process, a condensation and/or polymerization of the oils takes place. It has been found that such condensation or polymerization produces products which,

have an increased solvent action on coal than 10% to 15% During the reaction of the oily materials mentioned above, with sulphur, a considerable quantity of hydrogen sulphide is given oil. From this gas, sulphur may be recovered by well known methods, such as by burning with a restricted air sup ly, or by liquid purification processes. bulphur obtained from this source is just as effective as sulphur from other sources.

It has been found that only very small quantities of sulphur remain in the materials after treatment, usually not more of the amount introduced into the reaction. In other words, the sulphur treatment does not introduce an obectlonable amount of sulphur into the final product. If desired, this small amount of sulphur may be reduced or removed by vatious treatments. For instance, the sulphur 1929. Serial 110,854,694.

treated material may be heated in an. autoclave'to' temperatures above the temperatures ordinarily used in the proccss'of this invention. I

In carrying out the process 'ot't-his inven-. tion, good results are obtainedby the additions of condensationaids, which have the effect of increasing the speedof the reaction andalso of removing sulphur. Such aids are either used duringthe reaction, or the sulphur treated materials are boiledwith the condensation aid under reflux. Compounds .such as zinc chloride, aluminum 3 chloride,

phur. The sulphur may beiadded to the oil: or tar andthe reaction brought about'or com pleted by introducing oxygen or air. In 'this Furthermore, the

reaction, apparently thesulphur reacts first,

then the hydrogen sulphide which isformed during the reaction is oxidized by the air or 7 oxygen, and the sulphur thus formed enters.

into the reaction again. While the, action of oxygen alone is somewhat slow, it may thus be speeded up by using the sulphur-asare,- A action carrier. In this Way, a very small amount of sulphur is sufficient for thek'rea tion, and this has its advantagesin cases wherethe presence of sulphur is objection able in the final product. i

Another alternative would be to introduce sulphur dioxide into the reaction j vessel where it would combine with the hydrogen sulphide evolved, thus forming sulphur dioxide maybe obtained by polymerization of sulphur which would enter the reactionagain'. The I burning hydrogen sulphide from another reaction above, may be car-1 of coal, whereupon} appear to exert a beneficial effect on the coal as well as on the solvents.

Examples of processes of th1s mventlon are as follows:

1. Onehundred'parts of crude water-gas tar or low-temperature carbonization tar are tically completed in a few hours. The reaction product may then be-used for dissolving coal.

2. "Eighty parts of crude watergas tar or low-temperature carbonization tar are heatedwith 8 parts of sulphur and parts of coal in a rotating autoclave. The temperature is graduallyincreased to 320 (3., and

I the'materialkept atthis temperature until the pressure has substantially ceased to in-.

crease. The'autoclave is then allowed to cool .down below 200 (Latter which the hydrogen sulphide is. allowed to escape and-the coal solution isdischarged.

7 3. Water-gas taror other ltars or oils and ten percent by ,weightof sulphur are mixed together and boiled vigorously under a re-. flux condenser for aboutv six hours or until hydrogen sulphide hasvceased to come ofi. Then about twenty percent by weight of freshly fused and crushed zinc chloride is added whereupon the mixture is boiled un-' v der er reflux condenser for about nine hours or until no more hydrogen sulphide comes 0 1i. 4 The resulting tar or oil product is allowed'to cool and is separated from the zinc chloride. i i

Water-gas tartreated in accordance with the process set forth-in Example 3, willcon-r v tainlessfsulphur than the original water-gas tar; The color of the tar is improved by the v treatment with zinc chloride, the tar is less and it'isra better solvent for coal than the viscousthan tar treatedwith sulphur alone,

original tar.

, Coal ;solutions made from tars or oils treated according to the process of this invention have, of course difierent character'- istics from those made from the same tars by topping and subsequentdissolving of coal in the distillation residue. Coal solutions ,madefrom treated oily materials are generally not ashard, although their melting I point may be quiteas high; and their temvperature susceptibility factor is lower.-

Weclaim as our invention: I 1. A process comprislng heatlng a mixture of water gastar and about 10 per cent of sulphur in the presence of coalup to about 320 30}; under pressure, gradually reducing the, temperature below 200 C.,

"reducingr'the pressure.-

, 2JA process comp s g befitting} 86 parts and then by weight of water-gas tar and 8sparts by 1 I weight of sulphur in the presence of 20 parts a 1 by weight of coal up to about'320 C. under-1 pressure, gradually reducing.the -te mpera- I i ture' below 200 0., and 'thenreducing the pressure. 7 I s In testimony whereof, we'have hereunto subscribed ournames this 8th; day o fn Lpril,

- HAROLD JJROSE;

WILLIAM H. HILL. 

